Two Mile Canyon
The Two Mile Canyon project includes an approximately 68 m dam with a spillway control structure, a fish ladder, a water intake, conveyance, a 3-unit powerhouse with 2 additional turbine and generator bays for post 2065 upgrades, trailrace structures and diversion tunnels to facilitate de-watering of the dam site during construction.
Costs are preliminary and are based on Class 5 engineering estimates.
They are used here to compare the relative costs of each site.
3.4 Two Mile Canyon [STEWA-HESS -0552]
Two Mile Canyon is a potential hydroelectric project on the Hess River, located in the Stewart River Basin approximately 100 km east of Mayo. The total drainage area is estimated to be 14,200 km2. The major components of the preliminary project layout are listed in Table 16. The project components are shown in Figure 8 and described in more detail as per sections listed in Table 16.
Table 16: Two Mile Canyon Major Project Components
15 – At this stage of study, upstream fish passage is expected to be facilitated via fish ladder. During subsequent phases of development, different alternatives may be considered including, but not limited to, mechanical lifts or trap-load-haul operations. Downstream fish passage is expected to be facilitated through fish friendly turbines (e.g. Kaplan Turbine).
16 – The transmission line is not shown on the drawing but is expected to follow approximately the access road from the switchyard to the interconnection point.
Figure 20: Two Mile Canyon Layout